Recently, sensors capable of detecting contact or approach of an object to be detected such as a finger have been put into practical use as a display device interface or the like. A capacitive touch panel, which is an example of the sensors, comprises an electrode for detecting a change in the electrostatic capacitance caused by the object to be detected. In a display device including such a touch panel, in addition to a flexible printed circuit connected to a display panel, a flexible printed circuit connected to a surface on which an electrode of the touch panel is formed is required.